Option 1 -> Alfred Marshall is known for his contributions to microeconomics and supply-demand analysis.
Option 2 -> J. S. Mill contributed significantly to political economy and utilitarianism.
Option 3 -> Adam Smith is called the founding father of modern economics for his seminal work 'The Wealth of Nations' (1776).
Option 4 -> John Maynard Keynes founded Keynesian economics in the 20th century.
Hence, Option 3: Adam Smith -> Adam Smith is universally recognized as the founding father of modern economics. His book 'An Inquiry into the Nature and Causes of the Wealth of Nations' (1776) laid the foundation for classical economics. He introduced key concepts such as the 'invisible hand' of the market, division of labor, free trade, and the self-regulating nature of markets. His work transformed economics from moral philosophy into a distinct social science. -> correct